[comp.os.vms] TK50/TK70

HANSHER@BATTELLE.ARPA ("MFG. SOFTWARE DEVEL. FAC. ", 11-9-093A) (01/22/88)

>> We have a TK70 tape which was 'init'd under RSTS/E on a PDP-11 (using a
>> TK-50 drive).  The tape now refuses to 'initialize' under VMS, failing with
>> the message "Software write protect"......
>> How do we recover from this one?

>I suspect you can't recover this tape.  The reason is that Digital says
>the TK70 drive can *read* TK50 tapes but not write them; I suspect (can't
>verify since we have no TK70s here) that if you inserted a TK50 tape into
>a TK70 drive, the tape would be "software write protected".

>As for you particular case, I'd guess that the RSTS system has made the
>tape look like a TK50 to the TK70 drive so its treating it like a TK50
>cartridge.  The only solution I can think of would be to bulk-erase the
>cartridge *HOWEVER, WARNING, READ THIS FIRST* I seem to remember that
>TK50s (and probably TK70s) are formatted at the factory and so bulk
>erasing would destroy the tape (maybe another reader can clear up this
>point).

Frank-
I have run into this problem here at Battelle.  An attempted INIT of
a TK70 cartridge (TK52-K) that was previously initialized to be a
"TK50" results in the above mentioned write protect problem.  An attempt
to write to the volume also results in a parity error.
    
I had the same idea that you had about bulk erasing.  Since TK52
cartridges are very, very hard to come by, I decided to give it a try.
Success!!!  The cartridge seems to be initializing, writing, and reading
fine.  
  
<<< Kevin M. Hansher
<<< Battelle Columbus Division